On Water-Spouts. - 263 



most 



part transparent, because they contain water; but experience 

 proves, as well as the very nature of the thing, that in the inte- 

 rior there is no connected mass of water. It would be more cor- 

 rect to say that water-spouts which come over sea are more rarely 

 opaque, because they can contain no dust, and hence can only 

 be so far opaque that they include numerous minute drops, or, 

 what is most usual, a portion of the fog-like cloudy mass. We 

 can, therefore, easily understand why the lower part of the mid- 

 dle portion of a water-spout becomes generally transparent at last, 

 viz., because the whirling movement becomes weakened, and the 

 cloud-funnel is hence shortened. 



We have seen that the air which is immediately above a wa- 

 ter-spout, must descend into that portion of it in which the air is 

 attenuated, and, therefore, in the vicinity of the axis more espe- 

 cially. If now, as we suppose, the whirlwind extends upwards, 

 far above the cloudy mass, in which mere observation would as- 

 sign its commencement, the descending air, coming from colder 

 regions, must condense the vapors which it meets with on its 

 path, and partly produce large drops and partly hailstones. We 

 can thus easily imagine that the frozen particles, during all these 

 movements, are sometimes out of contact with warmer and moist 

 ah-, and also that they are again equally often brought back to 

 situations where they meet them, so that alternately they become 

 so much cooled that the water by which they are coated becomes 

 ice, or they meet moist air in which they acquire a new covering 

 of water. Hence large hailstones may be formed, composed of 

 various layers, the one including the other. 



All this corresponds in the most remarkable manner with the 

 facts observed. Great storms of hail and violent showers of rain 

 almost invariably accompany water-spouts. It may, perhaps, not 

 be too bold to suppose, that the great falls of hail, which so fre- 

 quently devastate long but narrow tracts of fruitful land, are pro- 

 duced by great air-vortices in the higher regions of the atmos- 

 phere, or, if I may be allowed so to express myself, by water- 

 spouts which extend beyond the lower strata of clouds. So far 

 as I can judge, no circumstance occurs during great showers of 

 hail, which does not harmonize with this idea. Electricity, 



as 



perhaps contribute by causing a greater variety of movements 



